External Attestation (third-party verification)

Goal: let a neutral party reproduce one Helix conformance pack and publish a signed result. This is a credibility artifact, not a product feature.

Minimal flow for an external lab/auditor

1. Download the repo or release artifacts plus repro/helix_repro_bundle_v1.
2. Install Helix (release build) in a clean env: python -m venv /tmp/helix-attest && . /tmp/helix-attest/bin/activate && pip install helix-governance[viz,schema].
3. Run the conformance pack: ./tools/conformance.sh (or python tools/conformance.sh on Windows).
4. Capture outputs: conformance.log, pytest.xml (if -q --junitxml is added), SHA256SUMS.txt for artifacts, and the environment fingerprint (python -V, uname -a).
5. Publish a signed attestation bundle (zip): log + hashes + SBOM of the installed wheel (syft helix-governance -o spdx-json).

Suggested template for published attestation

• Who ran it (organization + contact)
• Helix version and commit/tag
• Platform (OS/CPU/GPU), Python version
• Command run, start/end time (optional)
• PASS/FAIL summary per test
• Hashes of all emitted files
• Signature (GPG) over the zip or a detached signature over the hash list

Where to stash attestations

• Repo path: attestations/<tag>/<org>-conformance.zip (add to .gitignore if large) or attach to GitHub Releases.
• Reference the attestation in CHANGELOG.md for that tag.

Notes

• Keep the pack small to make attestation cheap; use the D0/D1 conformance runner by default.
• External attestation should be repeatable offline once artifacts are downloaded.
• If an attestation fails, file it via SECURITY.md channels and publish remediation once fixed.